Can you tell me when people first started calling the whiteness in the night sky the Milky Way?
The earliest known uses in English of both the words Milky Way and galaxy are found together, in the following lines from a poem by Geoffrey Chaucer called "The House of Fame," written sometime before 1385: "Se yonder, loo, the Galaxie,/Which men clepeth the Milky Wey,/For hit ys whit." (See yonder, lo, the galaxy, which they call the Milky Way, because it is white.) These lines make it clear that Milky Way was a term popular in England before that time, though how early is impossible to say. The idea of the whiteness of the Milky Way being similar to that of milk is considerably older than the English language, however, for galaxy is borrowed through Latin from Greek galaxias, a derivative of gala, meaning "milk." Not until the 19th century was galaxy used as a generic term for other star systems as well as the one in which we live, and to distinguish our galaxy from others the name Milky Way has proved useful.